Copper(II) inhibits the formation of amylin amyloid in vitro

The amyloidogenic peptide amylin is found associated with pancreatic islet β-cells and is implicated in the aetiology of type-2 diabetes mellitus. We have used fluorimetry and transmission electron microscopy to investigate in vitro the influence of Al(III), Fe(III), Zn(II) and Cu(II) on amylin amyloid formation under near-physiological conditions. Cu(II) at 10.0 μM inhibited amylin of 0.4 and 2.0 μM from forming amyloid fibrils while the same concentration of either Al(III) or Zn(II) promoted the formation of β-pleated sheet structures. If amylin amyloid is cytotoxic to β-cells then Cu(II) should protect against the degeneration of the islets in type-2 diabetes mellitus.